Playboy: Medical and Martial Master - Chapter 322 - 321: Yao Yuelong [Double-Length]

Once I’ve become Immortal, then my attempt to conquer the world shall begin.

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

Cultivation destroyed, eyes poisoned blind and robbed of her status in the household?Luo Qingtong narrows her eyes and sneers, “Bring it on! Let me teach you a lesson!”A 24th Century Supreme Vision Master transmigrates to become the incapacitated genius daughter of the Marquis Household in a lower-class country.With a pair of powerful blood-red eyes armed with the ability to appraise treasures, see through things, heal, poison and break through defenses... She is invincible!A spirit and martial arts cultivator, an expert in weapons and medicine, a master in controlling beasts and deploying formations...She is the embodiment of the ultimate supremacy and unrivaled arrogance!Never does she expect to get involved with a person who is even more wicked than her. From then on, it becomes a game of I-run-you-catch. When you kill someone, I’ll hand you the knife.Together, let’s wreak havoc in the world!

Damien Julian is an 18-year-old loser, who has been bullied and mistreated his entire life, at home, he has to deal with his abusive father, and at school, he is constantly been bullied by delinquents, and to make things worse he is always looked down upon by his peers, till one day a mysterious screen appear before him as it said.

[The world has seen the lingering evil in your heart]

[Would you like to be one of the nine demon kings of this world]

[If so what are you willing to sacrifice?]

In the heat of the moment, Damien made a deal with the world, that he would give up everything he owns, or do anything it wants, and in exchange, he shall be reborn as a new Demon King, and what the world required from him as payment was.

[In exchange for power, become a slave of the world, and act as an anti-body for all eternity]

At that moment, Damien agreed, but little did Damien know, that becoming a slave to the world meant he has to be its immune system, what that entail is, that anything that threaten the world must be destroyed even if he has to wipe out humanity, to save it, or assassinate historical figures to bring fort balance or even manipulating events that can potentially end the world, to save the world, this is the story of a necessary evil, not the story of a hero who cares for others.